minix/kernel/system/do_schedctl.c
2010-07-13 15:30:17 +00:00

45 lines
1.2 KiB
C

#include "kernel/system.h"
#include <minix/endpoint.h>
/*===========================================================================*
* do_schedctl *
*===========================================================================*/
PUBLIC int do_schedctl(struct proc * caller, message * m_ptr)
{
struct proc *p;
unsigned flags;
unsigned priority, quantum;
int proc_nr;
int r;
/* check parameter validity */
flags = (unsigned) m_ptr->SCHEDCTL_FLAGS;
if (flags & ~SCHEDCTL_FLAG_KERNEL) {
printf("do_schedctl: flags 0x%x invalid, caller=%d\n",
flags, caller - proc);
return EINVAL;
}
if (!isokendpt(m_ptr->SCHEDCTL_ENDPOINT, &proc_nr))
return EINVAL;
p = proc_addr(proc_nr);
if ((flags & SCHEDCTL_FLAG_KERNEL) == SCHEDCTL_FLAG_KERNEL) {
/* the kernel becomes the scheduler and starts
* scheduling the process.
*/
priority = (unsigned) m_ptr->SCHEDCTL_PRIORITY;
quantum = (unsigned) m_ptr->SCHEDCTL_QUANTUM;
/* Try to schedule the process. */
if((r = sched_proc(p, priority, quantum) != OK))
return r;
p->p_scheduler = NULL;
} else {
/* the caller becomes the scheduler */
p->p_scheduler = caller;
}
return(OK);
}